hello,

I want to design a multistandard LNA for 2.4GHz and 5.8GHz. Does anybody have an idea how I can design a matching network which is broadband and covers the desired frequency range or a network, which only works for theese two frequencies well ? Is there a special literature you can suggest ? Thanks for answers.

Yes I studied some papers about this topic. There are some possibilities to realize it. First, you design a broadband amplifier. Second, you design an amplifier with a switchable matching network and third is you design an amplifier where your matching network works well for two frequencies. In the last case you could not calculate the matching network because the input impedance of the transistor is changing for the two frequencies of interest, so you couldn't calculate it. Has somebody an idea, how i could calculate it ?

2 ways to do multi-standard frontend :
Either going broadband or narrowband. Broadband design needs very high linearity to handle strong signals. Narrowband design needs multiple LNAs for different bands. In your case, 2.4G/5.8G is too wide band to consider one single narrowband circuit. The compromise is too large to be acceptable.